from django.shortcuts import render, get_object_or_404
from django.template import loader
from django.http import Http404
from django.urls import reverse
from .models import Question, Choice

# Create your views here.
from django.http import HttpResponse, HttpResponseRedirect

def index(request):
    latest_question_list = Question.objects.order_by('-pub_date')[:5]
    context = {'latest_question_list': latest_question_list}
    return render(request, 'polls/index.html', context)

def detail(request, question_id):
    # try:
    #     question = Question.objects.get(pk=question_id)
    # except Question.DoesNotExist:
    #     raise Http404('Question does not exist')
    #使用快捷函数
    question = get_object_or_404(Question, pk=question_id)

    return render(request, 'polls/detail.html', {'question': question})

def results(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    return render(request, 'polls/results.html', {'question': question})

def vote(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    try:
        selected_choice = question.choice_set.get(pk=request.POST['choice'])
    except (KeyError, Choice.DoesNotExist):
        return render(request, 'polls/detail.html', {
            'question': question,
            'error_message': 'You did not select a choice'
        })
    else:
        selected_choice.votes += 1
        selected_choice.save()
        return HttpResponseRedirect(reverse('polls:results', args=(question.id,)))


